Drill bit remover



Patented Jan. 5, 1954 DRILL BIT REMOVER Heinrich Bartholomae, Herne, Germany, asslgnor, by mesne assignments, to Firma DipL- Ing. Friedrich Heinrich Flottmann, Bochum,

Germany Application May 23, 1950, Serial No. 163,617

This invention relates to a device for removing a shell annular bit (boring tip) from its shaft. In rock drilling there are often used drills the annular bits of which are slid over the conical ends of their boring bars so that they may be ex changed. As the rear ring-shaped face of such an annular bit is comparatively small the annular bit does not always permit of being removed from the boring bar by hammer blows only by which it might, in addition, be damaged. To ensure an annular bit of being more easily exchanged special appliances are used which being laid round the boring bar rest on the rear face of the annular bit, said appliances offering a sufficient space for hammer blows.

It is an object of this invention to provide a device which though its construction is simple and cheap and insensible to awkward usage offers the advantage that it rests on the whole circumference of the annular bit for ensuring an even transmission of the striking effect of a hammer, and that the annular bit to be removed from its shaft is caught so as to prevent it from falling into the mine ore which would necessitate long searching in view of the fact that lighting is bad at the face of a mine.

These objects are achieved by known devices in part only. Devices are known in which a ring shaped part, connected detachably with a catch box on its front side and widening conically towards its end, is provided on one side with a slot which enables the appliance to he slid like a fork laterally over the boring bar. Although the annular bit to be removed is securely caught said appliance has the disadvantage that the annular bit is attacked from one side only at its front face which renders the removing of the annular bit rather diiiicult. Other appliances in which said disadvantage is avoided are provided with a striking piece consisting of two ring segments enclosed by a sleeve like coupling piece. The segments rest on the whole circumference of the rear face of the annular bit. Prior to the ring segments being put on the coupling piece is slid over the boring bar and then moved over the segments from behind as far as it is stopped by a shoulder attached to the segments. According to this design the annular bit is, however, not catched and what is still more disadvantageous the parts of the appliance fall asunder after the annular bit is struck off so that they are liable to be lost.

In order to solve the problem, this invention is based on the design referred to above according to which a striking piece enclosing the boring shaft is connected with a box receiving the an- 2 Claims. (Cl. 29275) nular bit; the invention, however, is characterized by the fact that in a manner known as such the striking piece consists of at least two ring segmentsenclosed by a coupling member, and that the coupling member is, in addition, capable of being held together with the segments in the direction of the axis so that all the parts of the device remain connected after being struck off from the boring shaft by hammer blows.

The inventive idea is realized in a preferred and most simple way by the catch box itself constituting the coupling member.

In case a special piece, e. g. a ring is intended for coupling the ring segments, the catch box is preferably subdivided axially according to the number of the ring segments, and each part of the box is rigidly fixed to a ring segment. In general it is best to use two striking piece segments only which extend over 180 of the circumferenoe. Of course, there may be more segments.

The catch box and the striking piece segments may for instance be coupled by means of a threaded connection or a bayonet catch. A simple design consists in that the catch box is provided at its rear end with a projecting shell with an interior thread for the striking piece segments with a corresponding exterior thread to be screwed in. If at least one of the two striking piece segmentsin case there are two-is provided with transverse pins or the like lying preferably tangential to the drill circumference and being guided in corresponding grooves of the other striking piece segment, there is ensured an exact position of the thread provided on the segments and a transmission of the striking force to either segment whereby the threaded connection is discharged.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing wherein a preferred embodiment of the present invention is clearly shown.

Figure 1 is a longitudinal section,

Figure 2 is a cross section in the direction of the line II-II of Figure 1.

The device illustrated in the drawing consists of the two striking piece segments l and 2 which enclose the drill shaft 3 like a sleeve and rest on the whole circumference of the ring-shaped front face 4 of the boring tip (annular bit) 5.

The forward end of the striking piece segments land 2 is provided with an exterior thread 6. At its end the catch box I enclosing the annular bit 5 is provided with a projecting sleeve 8 provided with an interior thread '6' corresponding to the guide pins E}, which are rigidly fastened to one of 5 the two segments and in gear with corresponding grooves 6% of thejothersegmentwhereby thecorrect axial position otthe segments isensured.

By means of one or a few eificient blows, in the direction of the arrow x, on the front face 15,

which is bread on account of the conicalshape of the striking piece segments, the boring tip (annular bit) is detached from-thacone of; the; drill shaft 3 and then caught :by} theicatch box Without leaving the scope. .of.:theinvention Lthe,1'5,

striking piece segments may have a shape different from that shown in the drawing,

I claim:

1. A device for removing drill bits from drill:

rods by impact comprising, at least two clamping 20 segments adapted to beloosely fitted,around the: drill rod and in engagement with ,the drillibit, each segment having a blow receiving-surfaceat one end and a surface atthe other endadapted to contact the drill bit, a coupling vmemberto 25 radially engage said clampinglsegments to main tainthem in position on the .drillrodand having 4 a a receptacle thereon to surround the drill bit, said coupling member holding the device on the drill bit and by applying force on the said other end of the segments the latter with the coupling memher and receptacle will be removed from the drill rod with the drill bit in the receptacle.

2; A-device asclaimedin claim 1, saidreceptacle and coupling member being integral and said coupling member engaging said clamping segments by means of a thread connection.

HEINRICH BARTHOLOBIAE.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,007,248 Smith Oct. 31, 1911 1,840,470 Schneider Jan. 12, 1932 2,031,814 Bedford Feb. 25, 1935 2,359,677 Reeves Oct. 3, 1944 2,454,771 Carr Nov. 30, 1948 FOREIGN PATENTS Number Country Date 407,873 Great Britain Mei-1229,1934 551,573 Great-Britain Dec. 13, 1940 

